High blood pressure also known as hypertension,
is often called the silent killer because many people unknowingly have had the disease
for years. In fact, right now approximately
50 million Americans have high blood pressure with an estimated cost of
treatment around $37 billion annually, and one-third (about 15 million people)
don't know it. The NHANES III national
health survey estimates the age adjusted prevalence for hypertension in the United States
between 1988 and 1991 was 32 % for the African American population and 23% for the
White and Mexican-American populations1.
Blood pressure is determined by the
amount of blood the heart pumps and the amount of resistance to blood flow in the
arteries. Increased fluid in the body
causes and increase amount of fluid in the blood vessels which in turn
increases blood pressure.

Narrow
or clogged blood vessels can also raise the blood pressure in a patient. The kidneys play a key role in keeping blood
pressure within the normal range. High
blood pressure, in turn, can affect the kidneys in a negative way and
potentially cause renal diseases.High
blood pressure not only causes damage to the kidney, but also causes the heart
to work harder which over time lead to damaged blood vessels.

If the blood
vessels in the kidneys are damaged, filtration may be
compromised/impaired.The increased
fluid in the blood vessels may then cause further increases in blood pressure
resulting in a dangerous cycle.Clinically,
hypertension is defined as have systolic pressure greater then 140 and
diastolic greater then 90 mm Hg2.

Hypertension is very important to diagnosis and treat because
it increases the individual’s risk of developing other complications such as:
heart disease, kidney disease and stroke3.
It is especially dangerous since it
often presents no warning signs or symptoms. Regardless of race, age, or gender, anyone can
develop high blood pressure. It is
estimated that one in every four American adults has high blood pressure1. Once
high blood pressure develops, it usually lasts a lifetime. You can prevent and control high blood
pressure by taking the appropriate actions. Of the patients diagnosed with hypertension
only 34% are under control4.

According
to the seventh report of the Joint National Committee (JNC 7), normal blood
pressure is classified as systolic less than 120mmHg and diastolic less than
80mmHg. Pre-hypertension is classified
as systolic between 120-139 and/or diastolic 80-89. Hypertension is broken down into stage 1 and
stage 2. Stage 1 is systolic 140-159 and/or
diastolic 90-99. Stage 2 is systolic ≥ 160 and/or diastolic ≥ 1005. It
has recently been reported that systolic pressure is a more significant
predictor of hypertension in
individuals over 50 to 60 years old6.

There
are many risk factors associated with hypertension, one being heredity;
patients who have one or both parents diagnosed with hypertension have an
increased risk of developing the condition. Genetic factors account for 30 % of
the variations in blood pressure in certain populations6.
There is also a relationship between
sodium intake and essential hypertension. Excess salt intake increases the likelihood of
hypertension, but alone is not sufficient enough to cause hypertension. Excess alcohol intake clearly increases the
likelihood of hypertension. Obesity
increases the chance of hypertension. Hypertension
also tends to be more severe and
more common in
African-Americans7.Some of the secondary causes of hypertension
are primary renal disease, use of oral contraceptives, individuals with
pheochromocytoma, primary hyperaldosteronism, endocrine disorders, Cushing’s syndrome and coarctation
of aorta8.

A
major complications associated with hypertension is the risk of heart failure
in individuals of all ages[10]. Individuals with hypertension have a greater
tendency to develop Left Ventricular hypertrophy[11].Hypertension
is the major risk factor for
stroke[12]. Another serious outcome of uncontrolled
hypertension is intracerebral hemorrhage[13]. Finally, chronic renal insufficiency and
end-stage renal disease are poor
health outcomes associated with hypertension[14].

Diagnosis:

According to United States
Preventive Service Task Force it is
recommended that individuals
over the age of 21 years get their blood pressure checked at each physician
office visit[15]. It is very important to have proper
measurement and interpretation of blood pressure in the management and
diagnosis of hypertension. Diagnosis of mild hypertension should not be made
until the blood pressure has been measured at least three to six times. These
measurements have to be evenly spaced over a period of weeks to months.Otherwise some patients that seem to be
hypertensive in their initial visit may actually turn out to be normotensive[16].

When
it is determined that an individual has hypertension, then evaluation needs to
be done to estimate if there has been any organ damage and also to assess risk of developing
cardiovascular diseases. A laboratory workup is often used in the diagnosis of hypertension because in some cases
there aren’t any external signs. The
testing that needs to be
performed are electrocardiogram, hematocrit, glucose, creatinine, electrolytes,
and urinalysis. It is also very
important to get a good history from the patient. When taking a history, one should be careful about paying attention to
details which might aid in the diagnosis of hypertension.The
physical examination is also a key component in the diagnosis of hypertension. The main goal of physical examination
is to look for signs of organ damage like retinopathy17.

Treatment:

Individuals that are afflicted with
hypertension should be treated with antihypertensive medications. Studies have shown that antihypertensive
medications have been associated with a 50 % decrease in heart failure. There is 20 % reduction in myocardial
infarction and 35 to 40 reductions in stroke. Overall there is about 56 % reduction in
coronary heart disease18. Before individuals are put on antihypertensive
medications appropriate nonpharmacological modifications and lifestyle changes should be attempted. After evaluation, if the hypertensive
individual does not have organ damage then it is recommended that the
individual be evaluated three to six
visits over a certain period of time19.
Individuals who have a systolic pressure that is over 140mmHg and diastolic
pressure that is over 90mmHg should be put on antihypertensive medication20.
Individuals with diabetes and chronic
renal failurethat have a blood
pressure that is over 130 mmHg or a diastolic pressure over 80 mmHg21 should also be treated with antihypertensive medications. According to the seventh Joint National Committee,
it is recommended that individuals with uncomplicated hypertension should be
treated with low-dose thiazide diuretics22.
These would include low dose thiazide
diuretics like hydrochlorothiazide or chlorthalidone23. Thiazides are especially recommended because they decrease urinary calcium
excretion24.If thiazide alone does not work in lowering
hypertension then the patient is usually placed on angiotensin converting
enzyme (ACE) inhibitor, angiotensin II receptor blocker (ARB), beta blocker, or
calcium channel blocker. Individuals can
be on both diuretics and ACE inhibitors or ARB25.

The Antihypertensive
and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study showed that a low dose
diuretic offers a better cardioprotection than an ACE inhibitor or calcium
channel blocker for risk factors like coronary artery disease, type II
diabetes, left ventricular hypertrophy, individuals which previous stroke or
myocardial infraction, cigarette smokers, atherosclerosis and hyperlipidemia26. ACE inhibitors are used in individuals with
heart failure and myocardial infarction.
It also has a protective effect on the
renal system. This class of drug should
be used in individuals with heart failure, myocardial infarction, type I diabetes,
left ventricular dysfunction and renal failure27.
Angiotensin II receptor blockers (ARB) are used in individuals that do not tolerate ACE inhibitors. One of the side effects of ACE inhibitor is
cough, which may cause individuals
to be put on ARBs28.Beta Blockersare given to individuals after acute
myocardial infarction. Beta Blockers is given to patients for atrial
fibrillation and control for angina. It
is also given to patients with
heart failure or left ventricular dysfunction29.
Calcium channel blockers (CCB) are administered to
individuals for control of atrial fibrillation and angina. CCB are also given to individuals with
obstructive airway disease30.

Prevention:

One of the well known prevention
method is to reduce the intake of dietary sodium and the Dietary Approaches to
stop hypertension (DASH) Diet. The
result of this study was published in New England Journal of Medicine. This study observed 412 individuals that were
randomly assigned to eat a control diet that is typical of Americans or the
DASH diet30.1. The participants ate their assigned diet for
30 days. This study included males and
females and individuals from different races. The results from this study showed that in the
control group reducing sodium from high to intermediate levels decreased systolic
blood pressure by 2.1 mm Hg and by an additional 4.6 mm Hg when decreasing to low
levels.Within the DASH group reducing
sodium from high to intermediate levels decreased systolic blood pressure by
3.4 mm Hg and by an additional 1.7 mm Hg if the participants reached a low
level of sodium.The effect of sodium
was observed in the individuals with hypertension and also individuals without
hypertension. The DASH diet
significantly lowered systolic blood pressure at each sodium levels. In comparison to the control diet, DASH diet
led to lower systolic blood pressure by 7.1 mm Hg in individuals without
hypertension and 11.5 mm Hg in individuals with hypertension30.4. This study showed that reducing sodium intake
to levels that are below the current recommendation of 100 mmol per day and the
DASH diet lowers blood pressure31.

Another study that
was published in the Annals of Internal Medicine titled “Effect of
Aerobic Exercise on Blood Pressure: A Meta-Analysis of Randomized, Controlled
Trials,” showed evidence that aerobic exercise reduces blood pressure in both
hypertensive and normotensive individuals. The study was a meta-analysis of randomized,
controlled trial to determine the effect of aerobic exercise on blood pressure.
This study included 2419 participants32.
The intervention and control group differed
only in aerobic exercise.The results
from this study showed that aerobic exercise was associated with a significant
reduction in mean systolic blood pressure. There was a reduction of about 4 mm Hg33. The reduction of blood pressure was associated
with aerobic exercise in both hypertensive and normotensive individuals and in
individuals that were overweight and normal weight. This data suggests that
physical aerobic exercise should be considered an important component of
lifestyle modification for the prevention and treatment of hypertension34.

The National High
Blood Pressure Education Program Coordinating Committee develops programs for
the Primary Prevention of Hypertension.Their current guidelines were published recently in JAMA34.5. This articles talks about the
current recommendations for primary prevention of hypertension which included
population based approach and an intensive targeted strategies focused on individuals
that are at high risk for developing hypertension. According to this report
both of these strategies are complementary and emphasize six approaches with
proven efficacy for prevention of hypertension. These include maintain normal
body weight, limit alcohol consumption, maintain adequate intake of potassium,
reduce sodium intake, increase physical activity, have a diet that is rich is
fruits, vegetable, and low fat diary products. Finally reduce the intake of
saturated and total fats. According to this report applying these standards to
the general population as part of public health and clinical practice can aid
in preventing hypertension from developing and can aid in the reduction of
blood pressure35.

The public health
sector needs to have prevention and intervention programs that aid in
decreasing the prevalence of hypertension among all Americans. Public health
efforts in particular need to develop education programs especially for
individuals from the lower socioeconomic group and individuals that are at high
risk of develop hypertension. If an impact is to be made in improving
hypertension, then comprehensive programs that include early education and
prevention tips to individuals about hypertension need to be developed. Another
component would be to have better adherence and compliance among patient
already afflicted with hypertension. By having these individuals better manage
their hypertension; they will be able to improve their overall health and
quality of life. This, in return, would have positive effect in the overall
health and well being of the community as a whole.

From the public
health point of view, developing and investing in education, prevention and
intervention programs for those individuals that are afflicted with
hypertension or at a higher risk of developing hypertension, can reap
benefits.There could be large savings
of resources in the long term36.Further, these types of programs will result
in citizens in the community who are healthier. This is an important initial step
to reaching the goals set by Healthy People 2010, particularly around
increasing quality and years of healthy life and beginning to eliminate health
disparities in the United
States.

Gerber, JC and Stewart, DL. Prevention and Control of hypertension and Diabetes in an underserved
Population through Community Outreach and disease management: A Plan of action.
Journal of the Association for Academic Minority Physicians, Vol. 9, No. 3,
July 1998: 48-52.